Work machines, such as those in the forestry industry, are often required to balance the amount of power distributed to various performance characteristics and operations. For instance, a machine may include a boom and work implement to complete a desired task. The amount of power produced by the engine is shared throughout the machine to move the machine along different terrain and also operate the boom and work implement. In some instances, it is desirable for the machine to travel at a high speed, whereas in other instances the machine may be stationary while work is being done by the boom and work implement. In any event, it is desirable to optimize machine performance.
Some machines utilize one or more hydraulic motors to provide torque to drive the machine forward and backward. The machine can include an engine that produces power and drives a hydraulic pump that provides hydraulic fluid to the one or more hydraulic motors. Each hydraulic motor can be a variable displacement motor, such that at a minimum displacement the machine can move at a high speed and at a maximum displacement the machine travels at a lower speed. At a maximum displacement, however, a greater amount of torque can be provided to drive the machine over difficult terrain, for example, a steep slope, etc.
The manner in which motor displacement is controlled on a variable displacement hydraulic motor is through a predefined “begin of regulation” pressure (BOR) that is adjustable but mechanically fixed and it is difficult to make any adjustments to this displacement setting. The BOR pressure is a defined pressure at which the motor displacement begins to increase due to an increased load on the motor. The lack of adjustability prevents the machine from performing at optimal levels of performance in nearly every possible scenario.
An infinitely variable hydraulic motor has motor displacement that is hydraulically controlled. Setting the BOR pressure mechanically provides a fixed pressure resulting in a fixed power curve. In the forestry environment, no two worksites are the same. The BOR setting is difficult to set on a single motor. It is even more difficult when an operator has to set BOR for two motors to the same settings, for example where the two motors power two tracks of the machine and if one motor is slightly different the machine will not steer straight and/or have poor performance. In addition, over the lifetime of a machine the mechanical BOR setting needs to be manually adjusted to account for motor wear.
It would be desirable to provide an operator with the ability to easily adjust the begin of regulation point for a motor to vary the power available for machine movement and the power available for other machine functionality without the use of tools or mechanical adjustment.